The word “menopause” is often used to describe the time of life following your first symptoms, but there’s more to it than that. Menopause doesn’t happen overnight.
Learn more: What’s the difference between perimenopause and menopause? »
During your reproductive years, you produce estrogen, progesterone, luteinizing hormone (LH), and follicle stimulating hormone (FSH). In the middle of your monthly cycle, LH, FSH, and estrogen work together, prompting your ovaries to release a mature egg during ovulation.
Ovulation can’t occur unless your hormone levels are within the optimal range. If the egg is fertilized, LH stimulates progesterone production to maintain the pregnancy.
Perimenopause
Perimenopause is a time of transition — the “change of life.” Your ovaries are starting to produce less estrogen and progesterone. LH and FSH levels are starting to rise as your ovaries are becoming less responsive to them.
As your hormone levels fluctuate, you may start noticing symptoms such as hot flashes and night sweats. Your periods are getting irregular in length and frequency. Your ovaries may release an egg some months, but not others.
Read more: Pregnancy during perimenopause »
Although your fertility is declining, you can still conceive. If you don’t want to get pregnant, you need to use birth control throughout perimenopause. This phase can last for several years.
Menopause
During perimenopause, your periods may seem to have stopped, but then they start up again. That can happen many times, which can trick you into thinking you’ve reached menopause even though you haven’t.
If it’s been an entire year since your last period, you’ve reached menopause. For most women, this occurs somewhere between the ages of 40 and 55, with an average age of 51.
Once you’ve reached menopause, your LH and FSH levels remain high and your estrogen and progesterone levels remain low. You no longer ovulate and you cannot conceive a child.
Postmenopause
Once you’re postmenopausal, your hormone levels will never again be in the suitable range for ovulation and pregnancy. Birth control is no longer necessary.
